I've got RD working fine on the LAN, but over WAN not so much.
Here's what I've done.

Got the public IP a OK
port forwarded either port 443 or 3398....saw two different recommendations on Microsoft articles about where RD is listening.

Using the Iphone app tried entering the gateway as either
public IP: port 443 or 3398
neither work.....
tried entering the gateway as
http:// public IPort but it didn't like the http://
Also in the router I chose TCP as the protocol.

RD on my Iphone is not finding the computer its not a log in problem its a "I can't find your computer" problem.
Using Microsoft Defender and checked the Firewall which is allowing RD two way communication.

What m I doing wrong????